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Yuanzheng-1
Yuanzheng () is a restartable upper stage developed by the China Academy of Launch Vehicle Technology (CALT) for the Long March rocket family. The Yuanzheng stage enables the Chinese launch vehicles to deploy payloads directly to high-energy orbits such as medium Earth orbit (MEO) and geosynchronous orbit (GSO). Since the Long March third stage cannot restart, it cannot circularize a GSO or GEO orbit from a geosyncronous transfer orbit ( GTO). With its restart capability, Yuanzheng has enabled the deployment of satellite pairs for the BeiDou Navigation Satellite System in MEO and communications satellites in GSO. This eliminates the need for the spacecraft to include a liquid apogee engine or an apogee kick motor. Yuanzheng has a thrust of with a specific impulse of 315.5 seconds. It uses the storable hypergolic propellants unsymmetrical dimethylhydrazine (UDMH) and dinitrogen tetroxide (), and can perform at least two burns within its rated life of 6.5 hours, sufficient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long March 7
, stages = {{plainlist, * CZ-7: Two * CZ-7A: Three {{cite web, url=https://www.space.com/china-space-program-new-long-march-rockets.html, last=Jones, first=Andrew, title=China prepares to launch new rockets as part of push to boost space program, publisher=SPACE.com, date=14 February 2020, access-date=14 February 2020 , capacities = {{Infobox rocket/payload , location = LEO (200 x 400 km x 42°) , kilos = {{cvt, 13500, kg {{Infobox rocket/payload , location = GTO , kilos = {{cvt, 7000, kg {{Infobox rocket/payload , location = TLI , kilos = {{cvt, 5000, kg {{Infobox rocket/payload , location = SSO , altitude = {{cvt, 700, km , kilos = {{cvt, 5500, kg , family = Long March , derivatives = , comparable = Delta IV, Atlas V, Falcon 9 Block 5, GSLV Mk.III, H-IIA , status = Active , sites = Wenchang, LC-2 , launches = 10 (7:6, 7A:4) , s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yuanzheng Upper Stages
Yuanzheng () is a restartable upper stage developed by the China Academy of Launch Vehicle Technology (CALT) for the Long March rocket family. The Yuanzheng stage enables the Chinese launch vehicles to deploy payloads directly to high-energy orbits such as medium Earth orbit (MEO) and geosynchronous orbit (GSO). Since the Long March third stage cannot restart, it cannot circularize a GSO or GEO orbit from a geosyncronous transfer orbit ( GTO). With its restart capability, Yuanzheng has enabled the deployment of satellite pairs for the BeiDou Navigation Satellite System in MEO and communications satellites in GSO. This eliminates the need for the spacecraft to include a liquid apogee engine or an apogee kick motor. Yuanzheng has a thrust of with a specific impulse of 315.5 seconds. It uses the storable hypergolic propellants unsymmetrical dimethylhydrazine (UDMH) and dinitrogen tetroxide (), and can perform at least two burns within its rated life of 6.5 hours, sufficient to r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long March 3B
The Long March 3B (, ''Chang Zheng 3B''), also known as the CZ-3B and LM-3B, is a Chinese orbital launch vehicle. Introduced in 1996, it is launched from Launch Area 2 and 3 at the Xichang Satellite Launch Center in Sichuan. A three-stage rocket with four strap-on liquid rocket boosters, it is currently the second most powerful member of the Long March (rocket family), Long March rocket family after the Long March 5 and the heaviest of the Long March 3 rocket family, and is mainly used to place communications satellites into geosynchronous orbits. An enhanced version, the Long March 3B/E or G2, was introduced in 2007 to increase the rocket's geostationary transfer orbit (GTO) cargo capacity and lift heavier geosynchronous orbit (GEO) communications satellites. The Long March 3B also served as the basis for the medium-capacity Long March 3C, which was first launched in 2008. , the Long March 3B, 3B/E and 3B/G5 have conducted 82 successful launches, plus 2 failures and 2 partial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long March 2D
The Long March 2D (), also known as the Chang Zheng 2D, CZ-2D and LM-2D, is a Chinese two-stage orbital carrier rocket mainly used for launching LEO and SSO satellites. It is manufactured by the Shanghai Academy of Spaceflight Technology (SAST). It is mainly launched from areas LA-2B and LA-4 at the Jiuquan Satellite Launch Center. The Long March 2D made its maiden flight on 9 August 1992. It was initially used to launch FSW-2 and FSW-3 reconnaissance satellites. Unlike all other members of the Long March 2 rocket family, the Long March 2D is a two-stage version of the Long March 4 The Long March rockets are a family of expendable launch system rockets operated by the China Aerospace Science and Technology Corporation. The rockets are named after the Chinese Red Army's 1934–35 Long March military retreat during the Ch ... launch vehicle. Launch statistics List of launches The Long March 2D made its maiden flight on 9 August 1992. References Exter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apogee Kick Motor
An apogee kick motor (AKM) is a rocket motor A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, in accordan ... that is regularly employed on artificial satellites to provide the final impulse to change the trajectory from the transfer orbit into its final (most commonly circular) orbit. For a satellite launched from the Earth, the rocket firing is done at the highest point of the transfer orbit, known as the apsis, apogee. An apogee kick motor is used, for example, for satellites launched into a geostationary orbit. As the vast majority of geostationary satellite launches are carried out from spaceports at a significant distance away from Earth's equator, the carrier rocket often only launches the satellite into an orbit with a non-zero inclination approximately equal to the latitude of the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Impulse
Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse is exactly proportional to the effective exhaust gas velocity. A propulsion system with a higher specific impulse uses the mass of the propellant more efficiently. In the case of a rocket, this means less propellant needed for a given delta-v, so that the vehicle attached to the engine can more efficiently gain altitude and velocity. In an atmospheric context, specific impulse can include the contribution to impulse provided by the mass of external air that is accelerated by the engine in some way, such as by an internal turbofan or heating by fuel combustion participation then thrust expansion or by external propeller. Jet engines breathe external air for both combustion and by-pass, and therefore have a much higher specific impulse than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypergolic
A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. The main advantages of hypergolic propellants are that they can be stored as liquids at room temperature and that engines which are powered by them are easy to ignite reliably and repeatedly. Common hypergolic propellants are difficult to handle due to their extreme toxicity and/or corrosiveness. In contemporary usage, the terms "hypergol" and "hypergolic propellant" usually mean the most common such propellant combination: dinitrogen tetroxide plus hydrazine and/or its relatives monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH). History In 1935, Hellmuth Walter discovered that hydrazine hydrate was hypergolic with high-test peroxide of 80-83%. He was probably the first to discover this phenomenon, and set to work devel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unsymmetrical Dimethylhydrazine
Unsymmetrical dimethylhydrazine (UDMH; 1,1-dimethylhydrazine, НДМГ or codenamed Geptil) is a chemical compound with the formula H2NN(CH3)2 that is used as a rocket propellant. It is a colorless liquid, with a sharp, fishy, ammonia-like smell typical for organic amines. Samples turn yellowish on exposure to air and absorb oxygen and carbon dioxide. It is miscible with water, ethanol, and kerosene. In concentration between 2.5% and 95% in air, its vapors are flammable. It is not sensitive to shock. Symmetrical dimethylhydrazine, 1,2-dimethylhydrazine is also known but is not as useful. Production UDMH is produced industrially by two routes. Based on the Olin Raschig process, one method involves reaction of monochloramine with dimethylamine giving 1,1-dimethylhydrazinium chloride: :(CH3)2NH + NH2Cl → (CH3)2NNH2 ⋅ HCl In the presence of suitable catalysts, acetylhydrazine can be N-dimethylated using formaldehyde and hydrogen to give the N,N-dimethyl-N'-acetylhydrazine, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinitrogen Tetroxide
Dinitrogen tetroxide, commonly referred to as nitrogen tetroxide (NTO), and occasionally (usually among ex-USSR/Russia rocket engineers) as amyl, is the chemical compound N2O4. It is a useful reagent in chemical synthesis. It forms an equilibrium mixture with nitrogen dioxide. Its molar mass is 92.011 g/mol. Dinitrogen tetroxide is a powerful oxidizer that is hypergolic (spontaneously reacts) upon contact with various forms of hydrazine, which has made the pair a common bipropellant for rockets. Structure and properties Dinitrogen tetroxide could be regarded as two nitro groups (-NO2) bonded together. It forms an equilibrium mixture with nitrogen dioxide. The molecule is planar with an N-N bond distance of 1.78Å and N-O distances of 1.19Å. The N-N distance corresponds to a weak bond, since it is significantly longer than the average N-N single bond length of 1.45Å. This exceptionally weak σ bond (amounting to overlapping of the ''sp''2 hybrid orbitals of the two NO2 units) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China Academy Of Launch Vehicle Technology
The China Academy of Launch Vehicle Technology (CALT) is a major state-owned civilian and military space launch vehicle manufacturer in China and one of the major launch service providers in the world. CALT is a subsidiary of the larger China Aerospace Science and Technology Corporation (CASC). It was established in 1957 by Dr. Xue-Sen Qian and is headquartered in Fengtai District, Beijing. Its major contribution to China's civilian and military launch capability has been the manufacture of the Long March family of rockets. CALT has 31,600 employees and at least 13 research facilities. The current Chief Designer is Long Lehao (). CALT is also planning two spaceplanes. They would both be single-stage to space sub-orbital rocketplanes. One would be a 10-ton 4-passenger plane that would fly to 100 km at Mach 6. The other would be a 100-ton 20-passenger plane that would fly to 130 km at Mach 8. They would be equipped with liquid methane/liquid oxygen rocket engines. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xichang Satellite Launch Center
The Xichang Satellite Launch Center (XSLC), also known as the Xichang Space Center, is a spaceport of China. It is located in Zeyuan Town (), approximately northwest of Xichang, Liangshan Yi Autonomous Prefecture in Sichuan. The facility became operational in 1984 and is used to launch numerous civil, scientific, and military payloads annually. It is notable as the site of Sino-European space cooperation, with the launch of the first of two Double Star scientific satellites in December 2003. Chinese officials have indicated interest in conducting additional international satellite launches from XSLC. In 1996, a fatal accident occurred when the rocket carrying the Intelsat 708 satellite failed on launch from the Xichang Satellite Launch Center. Also, a 2007 test of an anti-satellite missile was launched from the center. History China's first crewed space program In order to support the Chinese Project 714 crewed space program in the 1960s, the construction of a new space ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geostationary Transfer Orbit
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellite, Satellites that are destined for geosynchronous orbit, geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step for reaching their final orbit. A GTO is highly Elliptic orbit, elliptic. Its perigee (closest point to Earth) is typically as high as low Earth orbit (LEO), while its apogee (furthest point from Earth) is as high as geostationary (or equally, a geosynchronous) orbit. That makes it a Hohmann transfer orbit between LEO and GSO. Larson, Wiley J. and James R. Wertz, eds. Space Mission Design and Analysis, 2nd Edition. Published jointly by Microcosm, Inc. (Torrance, CA) and Kluwer Academic Publishers (Dordrecht/Boston/London). 1991. While some geostationary orbit, GEO satellites are launched direct to that orbit, often the launch vehicle lacks the power to put both the rocket and the satellite into that orbit. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
